High speed data communications networks utilize optical fiber cables for data transmission between information system units such as computers, mass data storage devices, and routers. Such units typically employ electrical connectors which couple to electrical connectors associated with electrical cables. To couple such units to an optical fiber cable, an electro-optical converter or transceiver is employed which interfaces between the electrical connector and the optical fiber cable.
Examples of electrical connectors know in the prior art communications applications are illustrated in FIGS. 1A and 1B. More particularly, FIG. 1A shows an electrical connector 10 designed for use in a 4-channel InfiniBand™ electrical interconnect. FIG. 1B shows an electrical connector plug 12 designed for use in a 12-channel InfiniBand™ electrical interconnect. Electrical connectors 10 and 12 are inserted in associated electrical receptacles mounted on an information systems unit to establish electrical contact with the input/output terminals of such unit.
FIGS. 2A and 2B respectively show an optical cable connector 14 and an optical cable connector receptacle 16 used in InfiniBand™ 4-channel and 12-channel optical interconnects. The optical connector 14 is adapted to mate with optical connector receptacle 16 to enable the four independent optical signals traveling through four fibers in the attached optical cable 18 to communicate with corresponding receivers disposed in the optical connector receptacle 16. The committee setting standards for both 10 Giga-bit Fiber Channel (10 GFC) and 10 Giga-bit Ethernet (10 GbE) is considering to use the above described electrical and optical connector plugs/receptacles in systems complying with these standards.
FIG. 3 shows a conventional InfiniBand™ interface card 20 that is adapted to be inserted in system 22. Depending on the function it is adapted to perform, the InfiniBand™ interface card 20 is commonly referred to as a Host-Channel Adapter (HCA) or a Target Channel Adapter (TCA). Each InfiniBand™ interface card 20 includes one or more printed circuit boards (PCB) that are alternatively referred to hereinbelow as host broads. Each such PCB typically includes hardware adapted to establish communication with other PCBs, with other interface cards or modules via a multitude of electrical wires or optical cables.
FIG. 4A shows an electrical connector receptacle 24 mounted on a host board 26 of a TCA/HCA card. Electrical connector receptacle 24 is adapted so as to mate with electrical connector plug 10 (also see FIG. 1A). FIG. 4B shows an optical connector receptacle 28 mounted on a host board 30 of a TCA/HCA card. Optical connector receptacle 28 is adapted so as to mate with optical connector plug 14 (also see FIG. 2A).
In conventional systems, the host board is often adapted to mate with either an electrical connector plug or an optical connector plug. If the host board is adapted to mate with an electrical connector plug and a subsequent need arises to carry the signals over distances longer than those for which electrical wires, i.e., copper may be used (InfiniBand™ specification calls for copper wire to be used for distances up to 17 meters), the user may need to replace the TCA/HCA card with a card adapted to receive an optical cable so as to be able to handle optical signals, thereby increasing cost. Similarly, if the host board card is adapted to mate with an optical connector plug, and a subsequent need arises to carry the signals over a relatively shorter distances, it may be more cost effective to replace the TCA/HCA card with a card adapted to receive a copper wire so as to be able to handle electrical signals.
Accordingly, media adapters have been developed to enable optical signals carried via an optical cable to be coupled to electrical receptacles. Such media adapters include a fiber optic cable with an electrical plug coupled to on one end and an optical plug coupled to another end. The electrical plug is adapted to mate with an electrical connector receptacle on a host board and the optical plug is adapted to mate with an optical connector receptacle. The electrical signals present on the electrical receptacle are converted to optical signals by a transceiver disposed in the media adapter and carried over fiber optic cable. Conventional media adapters are connectorized and are thus relatively expensive. Furthermore, safety issues remain a concern if a user detaches the optical cable from the coupling plugs and looks at the light beams emanating from the lasers disposed therein.